YouTube is rolling out 4K support for Apple TV 4K devices, at least according to some Reddit users. From screenshots uploaded by these users, 24/30fps videos seem to be available in full 4K. However, it seems 60fps videos only seem to be available up to 1440p. According to the YouTube stats, all of these videos are playing in Google's VP9 codec. Image by u/vulcan_on_earth One big omission here is HDR. Even when playing videos that were uploaded in HDR, YouTube is still serving the SDR version. When Apple TV 4K was first launched three years ago, it supported 4K HDR playback...
Source: https://www.gsmarena.com/4k_youtube_starts_rolling_out_to_some_apple_tv_4k_users-news-45623.php
